The Cyr wheel (also known as the roue Cyr, mono wheel, or simple wheel) is an acrobatic apparatus that consists of a single large ring made of aluminum or steel with a diameter approximately 10 to 15 cm (4 to 6 in) taller than the performer. The performer stands inside the Cyr wheel and grasps its rim, causing it to roll and spin gyroscopically while performing acrobatic moves in and around the rotating wheel. The apparatus and its movement vocabulary have some similarities with the German wheel, but whereas the German wheel consists of two large rings linked together by horizontal crossbars and has handles for the performer to hold onto, the modern Cyr wheel consists of a single ring and has no handles. The Cyr wheel takes its name from Daniel Cyr, who reinvented it as a circus apparatus